Square obturator



Dec. 24, 1968 R. HAYDEN SQUARE OBTURATOR Filed April 17, 1967 INVENTORRODNEY HAYDEN United States Patent 3,418,609 SQUARE OBTURATOR RodneyHayden, Stoney Creek, Ontario, Canada, assignor, by mesne assignments,to United-Carr Incorporated, Boston, Mass., a corporation of DelawareFiled Apr. 17, 1967, Ser. No. 631,527 Claims priority, applicationCanada, Feb. 28, 1967,

83,944 6 Claims. (Cl. 335-203) ABSTRACT OF THE DISCLOSURE A squareobturator primarily for use in an electric relay formed from acontinuous strip of low carbon steel having a projecting tongue whichcarries a contact, and so constructed that it can be easily adjustedaccurately and then set to hold this adjustment after the manufacture ofthe relay.

Background of the invention An obturator is included in an electricrelay to control the gap across a pair of contacts. Thus a part of theobturator may constitute the armature of the relay. It has been thepractice for manufacturers of these devices to provide various set screwarrangements for controlling the gap across the contacts. Sucharrangements have been recognized as being undesirable because of themanufacturing costs involved.

It has been proposed to provide an obturator of the type noted includinga fixed base and a movable top piece spaced from the base and joinedthereto by an arcuate back that is designed and constructed to maintainthe contacts in a desired spaced relation. However, considerabledifficulty has been experienced in imparting the required physicalproperties to the arcuate back piece and particularly in accuratelyachieving the necessary curvature thereof.

Summary of the invention With these conditions in mind the presentinvention has in view, as its foremost objective, the provision of anobturator of the character noted which is essentially of rectangularshape. More in detail the invention provides an obturator comprising afront vertical wall, a flat base integrally joined to the front wall bya bend, a substantially straight rear wall integrally joined to the baseby a bend, and a fiat top wall integrally joined to the upper edge ofthe rear wall and extending over the upper edge of the front wall fromwhich it is spaced at an appropriate distance. This top wall carries aforwardly projecting tongue which in turn carries one of the contactsaforesaid.

The top wall is movable because of the flexibility of the bends at theupper and lower edges of the rear wall and, due to the elastic nature ofthe material from which the obturator is produced, will always exhibit atendency to return to a normal position to properly correlate thecontact on the projecting tongue with respect to a complemental contactmounted on the same panel which carries the obturator.

The top wall of the obturator constitutes the armature of the relay andis moved under the influence of the coil thereof. One important objectof the invention is to provide highly simplified means for limitingmovement of the armature. Downward movement is limited by the upper edgeof the front wall and upward movement by a detent in the form of aflange on a tab that extends upwardly from the front wall through anaperture formed in the top wall.

It is evident that the bends at the edges of the rear 3,418,609 PatentedDec. 24, 1968 wall determine the normal position of the top wall and aresusceptible of production by conventional manufacturing processes toaccurately position the top wall with respect to the base.

It may be deemed desirable to confine the flexing of the bends to asingle bend at either edge of the rear wall to achieve more accuratepositioning of the top wall. This may be accomplished by striking one ormore kerf-like deformations in either bend whereby a rigid relationbetween the rear wall and the other element at the bend is established.

Various other more detailed objects and advantages of the invention,such as arise in connection with carrying out the above noted ideas in apractical embodiment, will in part become apparent, and in part behereinafter stated, as the description of the invention proceeds.

For a full and more complete understanding of the invention referencemay be had to the following description and accompanying drawing.

Brief description 0 the drawing FIG. 1 is a perspective of an electricrelay including a rectangular obturator designed in accordance with theprecepts of this invention;

FIG. 2 is a perspective of a modified form of obturator per se; and

FIG. 3 is a perspective of still another modification.

Description of the preferred embodiment Referring now to the drawing,wherein like reference characters denote corresponding parts and firstmore particularly to FIG. 1 an electric relay is therein identified inits entirety by the reference character R. It includes a panel 10 whichordinarily is of insulating material.

Formed in the panel 10 is a slot 11 and passing therethrough is a stripconductor 12 which is bent over the upper face of the panel 10 asindicated at 13 with the bent portion 13 being anchored to the panel 10as depicted at 14. Upstanding from the portion 13 is a leg 15 andsecured to the upper end thereof is a carrier 16 provided on its upperface with a contact 17.

An obturator is referred to in its entirety by the reference character0. It is made of a continuous strip of spring metal of a low carbonferrous material of high hardness. A good example of such a material islow carbon steel, especially 1010 tin plate rolled to one quarter hardwidth and thickness and having a Rockwell hardness of about 52.

The obturator 0 comprises a front wall 18 to the lower edge of which isintegrally joined a base 19. Upstanding from the rear edge of the base19 is a rear wall 20 which is integrally connected to the base 19 by abend 21. A top wall 22 is integrally joined to the upper edge of therear wall 20 by a bend 23. This top wall 22 extends over the top edge ofthe front wall 18 from which it is spaced a distance that is accuratelypredetermined for the particular relay into which it is to be installed.

The top wall 22 has a front edge 24 and formed in the top wall 22 andspaced from this front edge 24 is an aperture 25. Forwardly of therecess 25 is a tongue 26 which carries a contact 27 on its underface.Extending upwardly from the upper edge of the front wall 18 with whichit is integrally formed, and through the aperture 25 is a tab 28 theupper end portion of which is turned forwardly to form a detent in theform of flange 29.

The coil of the relay is identified at 31 and is shown a beingpositioned within the obturator on the base 19 with its core 30 beingspaced from the top wall 22 which constitutes the armature of the relay.

When the coil 31 is energized the armature 22 is pulled downwardlycausing the contact 27 to engage the contact 17. Such engagement may beaccompanied by a slight flexing of the tongue 26 but any undue bendingis inhibited 3 by engagement of the top wall 22 with the upper edge ofthe front wall 18.

When the coil 31 is de-ener-gized the elastic qualities of the metalfrom which the obturator is formed, and particularly at the bends 21 and23 will cause the armature 22 to move upwardly into its normal openposition in which the contacts 17 and 27 are spaced. Such upwardmovement is limited by the detent 29.

Should it be desired to confine the flexing action to the bend 23 andestablish a substantially rigid relation between the base 19 and rearwall 20 resort may be had to the modification illustrated in FIG. 2. Inthis embodiment the bend 21 is shown as being deformed to providekerf-like formations 32 which are struck from the metal of the bend andadjacent wall portions. These deformations materially impair theflexible property of the bend 21 and establish a rigid relation betweenbase 19 and wall 20.

Likewise if it is desired to confine the flexing to the bend 21 andestablish a rigid relation between the rear wall 20 and top wall 22 theconstruction depicted in FIG. 3 may be employed. In this form of theinvention kerf-like deformations 33 are struck from the bend 23.

While a preferred specific embodiment of the invention is hereinbeforeset forth it is to be clearly understood that the invention is not to belimited to the exact constructions, mechanisms and devices illustratedand described because various modifications of these details may beprovided in putting the invention into practice within the purview ofthe appended claims.

I claim:

1. For use in an electric relay including a panel of insulating materiala fixed contact mounted on the panel and a coil, a substantiallyrectangularly shaped obturator mounted on said panel and receiving saidcoil, said obturator being fashioned from a continuous strip of lowcarbon steel and comprising: a front wall having an from said front wallby a bend; a top wall constituting an armature for said coil andintegrally joined to the upper edge of said rear wall by a bend, saidtop wall extending over said coil and the upper edge of said front wallin spaced relation with respect thereto; a tongue carried by said topwall and extending forwardly thereof; a contact on the underface of saidtongue and in spaced relation to said first mentioned contact with whichit is adapted to engage; said top wall being formed with an apertureadjacent to the front edge thereof; a tab on said front wall passingthrough said aperture; and a detent carried by said tab and adapted forengagement by said tongue to limit upward movement thereof, said bendsbeing adapted to flex when said coil is energized to move said armatureand bring said contacts into engagement and return the armature to itsnormal condition when the coil is de-energized under the influence ofthe elastic property of the steel from which said obturator is made.

2. The obturator of claim 1 in which the tongue is integral with the topwall and the tab is integral with the front wall.

3. The obturator of claim 1 in which the detent takes the form of aflange bent from and integral with the tab.

4. The electric relay of claim 1 together with a metallic plate that isinterposed between said base and the upper face of said panel.

5. The obturator of claim 1 in which one of said bends is deformed toprovide a kerf-like deformation which imparts rigidity to the bend.

6. The obturator of claim 1 in which one of said bends is deformed toprovide spaced kerf-like deformations which rigidify the bend.

References Cited UNITED STATES PATENTS 3,308,407 3/1967 Lake 335-2033,340,487 9/1967 Gruner 335-203 BERNARD A. GILHEANY, Primary Examiner.

H. BROOME, Assistant Examiner.

